These are the parallel series or representative groups
of naturalists, and they often occur in different countries, or
are found fossil in different formations.... We thus see how
difficult it is to determine in every case whether a given
relation is an analogy or an affinity, for it is evident that as
we go back along the parallel or divergent series, towards the
common antetype, the analogy which existed between the two groups
becomes an affinity.... Again, if we consider that we have only
the fragments of this vast system, the stems and main branches
being represented by extinct species of which we have no
knowledge, while a vast mass of limbs and boughs and minute twigs
and scattered leaves is what we have to place in order, and
determine the true position each originally occupied with regard
to the others, the whole difficulty of the true Natural System of
classification becomes apparent to us.
We shall thus find ourselves obliged to reject all those systems
of classification which arrange species or groups in circles, as
well as those which fix a definite number for the division of each
group.
Pages:
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158